Spin in Published Biomedical Literature: A Systematic Review

Quinn Grundy,1 Kellia Chiu,1 Lisa A. Bero1

Objective To explore the nature and prevalence of spin in the biomedical literature.

Design In a systematic review and meta-analysis, we searched MEDLINE, PreMEDLINE, Embase, Scopus, and handsearched reference lists for all articles published between 1946 and 24 November 2016 that included the quantitative measurement of spin in the biomedical literature for at least 1 outcome. Two independent coders extracted data on the characteristics of articles and included studies, methods for assessing spin, and all spin-related results. The data were heterogeneous; results were grouped inductively into outcome-related categories. We had sufficient data to use meta-analysis to analyze the association of industry sponsorship of research with the presence of spin.

Results We identified 4219 articles after removing duplicates and included 35 articles that investigated spin: clinical trials (23/35, 66%); observational studies (7/35, 20%); diagnostic accuracy studies (2/35, 6%); and systematic reviews and meta-analyses (4/35, 11%), with some articles including multiple study designs. The nature and manifestations of spin varied according to study design. We grouped results into the following categories: prevalence of spin, level of spin, factors associated with spin, and effects of spin on readers’ interpretations. The highest, but also greatest variability in the prevalence of spin was present in trials (median, 57% of main texts containing spin; range, 19%-100% across 16 articles). Source of funding was hypothesized to be a factor associated with spin; however, the meta-analysis found no significant association, possibly owing to the heterogeneity of the 7 included articles.

Conclusions Spin appears to be common in the biomedical literature, though this varies by study design, with the highest rates found in clinical trials. Spin manifests in diverse ways, which challenged investigators attempting to systematically identify and document instances of spin. Widening the investigation of factors contributing to spin from characteristics of individual authors or studies to the cultures and structures of research that may incentivize or deincentivize spin, would be instructive in developing strategies to mitigate its occurrence. Further research is also needed to assess the impact of spin on readers’ decision making. Editors and peer reviewers should be familiar with the prevalence and manifestations of spin in their area of research to ensure accurate interpretation and dissemination of research.

1Charles Perkins Centre, Faculty of Pharmacy, The University of Sydney, Sydney, New South Wales, Australia, quinn.grundy@sydney.edu.au

Conflict of Interest Disclosures: Dr Bero is a member of the Peer Review Congress Advisory Board but was not involved in the review or decision for this abstract.